Watch: Troye Sivan Reacts to Teens Reacting to Troye Sivan

Troye Sivan appeared on the popular "REACT" series on YouTube to watch a group of teen fans react to his popular debut album "Blue Neighborhood" and the powerful music videos that accompanied his songs.

One fan in particular — Sergio — really impacts Sivan.

"Watching him get sad about this, really makes me sad," the singer said when he watches the fan react to the "Blue Neighborhood" video trilogy.

"It fires me up. Seeing people that don't know that I'm watching them have real honest reactions to something that I've made and care about so much is so crazy," Sivan says.

Also in the video, the singer talks about transitioning from a YouTube star to a musician and the latest chapter in his journey — an actor. Sivan appears in the upcoming gay conversion therapy drama "Boy Erased" alongside Lucas Hedges, Nicole Kidman, Russell Crowe and more.